The next-generation Mercedes-AMG G63 has been spied undergoing testing, and these latest spy photos give us our first look at the interior of the new G-Class.

There are plenty of temporary coverings scattered across the cabin, including a leather hutch over the main set of air conditioning and infotainment controls.

The interior features the company's latest air vents, switchgear and infotainment equipment, as well as the line's signature dashboard hand grip for the front passenger.

Compared to the prototype of the regular G-Class SUV spotted in the middle of the 2016, this car has a deeper front bumper with larger air intakes. This car also has twin exhaust outlets under the rear doors and seems to feature wider wheel arch extensions.

Even with the full body camouflage, we can see the new G-Class won't be ditching its now iconic boxy styling. The upright windscreen and blunt profile gives little to aerodynamics or modern design trends.

Despite looking a lot like today's car, which traces its roots back to the 1979 G-Wagen, the car's underpinnings are thought to be largely new and significantly wider. Lightweight materials, such as high-strength steel and aluminium, should help to reduce to weight by up to 400 kilograms.

Under the bonnet, the new G63 should feature AMG's latest 4.0-litre twin-turbo V8. It's unknown how the motor will be tuned for the next-generation G-Class, but it will probably feature a setup similar to either 420kW/750Nm version used in the E63 and the 450kW/850Nm E63 S.

It's not known when the new G-Class will debut, but a reveal either at the end of this year or the beginning of 2018 seems likely.

Production of the new SUV will likely be outsourced to Magna Steyr's Austrian factory. It's possible the current G-Class will remain in production alongside the new car.